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DARYN KAGAN, CNN ANCHOR: We begin our hour with the breaking news out of London and word from Scotland Yard that there have been a number of arrests in connection with a raid in London where police say they found a very toxic substance. The substance, a toxic poison known as ricin. Five men arrested, one woman, she was also later released, but police saying that ricin is this toxic substance that comes from the castor bean, considered very lethal.

In terms of what plans, what plans there were for this, and other information, perhaps, we can get that now from our Nic Robertson, who is on the phone now from London -- Nic, hello.

NIC ROBERTSON, CNN SENIOR INTERNATIONAL CORRESPONDENT: Daryn...

KAGAN: Oh, he is live with us. Nic, hello.

ROBERTSON: Well, Daryn, these arrests -- Daryn, good morning. These arrests took place in London in the early hours of Sunday morning. Now, the police here say that six men and one woman were arrested in those raids. Those raids taking place in the north and east of London.

Now, one of those locations, where one man had been staying, that was Woodgreen in the north of London, they found traces of a substance called ricin.

Now, ricin is a toxin. It is like a biological agent. It is derived from the castor bean, and according to experts here, the ricin toxin can be made very, very easily from the castor beans. It is simply a matter -- a process of boiling it down. It is an incredibly toxic substance, less than a pin head is all that experts say is required to kill someone.

The ricin, also, there is no known cure for the ricin toxin, and it debilitates the body, breaks it down, and eventually kills whoever has been poisoned with this substance.

Now, the police at this time are only saying that these people were arrested. There are no other details. They're not saying who they were. They're saying their ages range between teenagers, some people in their 20s, some people in their 30s, but the details do not go beyond that at this time, only that at one of the locations where one of the men was staying was a substance that has been analyzed to -- believed to contain ricin -- Daryn.

KAGAN: So Nic, no word yet on the nationality of those arrested?

ROBERTSON: No word on the nationalities, no word of how the seven different individuals were -- no information on how these seven people were related to one another, only that these arrests occurred in the early hours of Sunday morning. So that's been two days now since these arrests took place -- Daryn.

KAGAN: Nic Robertson in London. Nic, thank you.

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